1. Field of the Invention
The present invention relates to electronic image processing and, more particularly, to a system for improving the quality of the output of full-color images reproduced on monitors that display a comparatively small number of colors, or printers that print a comparatively small numbers of colors, using halftoning and error diffusion techniques wherein the quantization error of one color of a given pixel is used to modify the quantization of the other colors of that pixel.
2. Prior Art
In full-color images, each pixel is typically represented as one of 16 million colors. However, in conventional electronic displays or computer monitors, such as those used for the IBM PS/2 with VGA, only 256 colors can be displayed. It is therefore a problem to obtain a top-quality display of full-color images on a monitor that can display only a small number of colors. Similarly, conventional printers are limited in the number of colors of a full-color image that can be reproduced. The present invention is directed to overcoming this color reproduction problem utilizing halftoning and error diffusion techniques.